Steam generating plant for the generation of high pressure steam



Sept. 1, 1931. K. ALLES smu GENERATING PLANI' FOR THE GENERATION or men rnsssuna swam Filed Jung 18. 1929 Inventor:

Kur't, Alles, 1

His AtLOFneg Patented Sept. 1, 1931 wire PATENT OFFICE KURT ALLES, F BERLIN, GERMANY, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A

CORPORATION OF NEW YORK STEAM GENERATING PLANT FOR THE GENERATION OF HIGH PRESSURE STEAM Application filed June 18, 1929, Serial No. 371,935, and in Germany July 14, 1928.

The present invention relates to steam generators and has for its principal object to provide an improved control means for regulating the operation of a high pressure "2 steam generator whereby the delivered, su-

.1' secure various other advantages to be hereinafter more fully pointed out and specified.

My invention is well adapted for use in connection with a steam generating plant such as that described in the application of '15 Petersen and Troger, Serial No. 358,319, filed April 26, 1929 for a steam generating plant for the generation of high pressure steam, and assigned to the same assignee as the present application, and I have illustrated i '20 and described it in connection with such a plant. It is to be understood,however, that the invention is not limited thereto necessarily.

In the drawings, Fig. 1 is a diagrammatic -';"25 view of an arrangement of a high pressure steam generator with a regulating means according to my invention applied thereto, and Fig. 2 is a similar diagrammatic view of a modification.

Referrng to the drawings, 6 indicates a boiler drum or evaporator which receives its feed water from a pump 3 through a preheater 4 and a conduit 5, said boiler drum being connected in a series circuit with a jet apij paratus 11 and a superheater 8. A conduit 7 conveys saturated steam from the drum 6 through the jet apparatus 11' to the superheater 8; '9 indicates a delivery conduitfor the useful supply of superheated steam and from this conduit apart of said superheated steam is diverted back to the boiler drum 6 through a conduit 10, to effect vaporization of the water in drum 6. High pressure superheated steam' is introduced to jet apparatus 11 from any convenient source through con duit 18,'as will be later described, and-mixed with the saturated steam fed to the jet apparatus 11 from the boiler drum 6. The superheated steam thus introduced is mixed in the. jet apparatus 11 with the saturated -maintain the delivered superheated steam at steam'in conduit 7 and gives a pressure increase in the series circuit such that the steam after traversing the superheater and sufl'ering the pressure drop therein there still exists an excess pressure sufiicient to force heated steam through return conduit 10 to the drum 6.

superheated steam of a pressure higher than that generated in boiler drum 6 is sup plied to the jet apparatus 11 by an auxiliary or special steam generating apparatus comprising a superheater 16 corresponding in function and arrangement to the superheater 8 and to which vapor is supplied by the jet apparatus 15 corresponding to jet apparatus 11. Water, heated preferably to the saturated steam temperature, is supplied to the jet apparatus 15 by a separate pump 12 and through a preheater 13, pump 12 being shown as being in series with feed water pump 3. A part of thesuperheated steam generated by the superheater 16 is fed through a conduit 17 to the jet apparatus 15 and the remainder of such superheated steam is fed to the jet apparatus 11 by conduit 18. The numeral 2, indicated in dotted lines, shows a furnace structure which encloses the various heating units. 19 and 25 indicate suitable regulating valves in conduits 9 and 18, it being understood that suitable regulating valves may be employed at such points in the system as found desirable.

In the system of regulating the operation of the above described generator in order to constant temperature, regardless of the conditions of load, a part of the heatin steam conveyed by conduit 10 is branched oil through a by-pass pipe 20 having a regulating member 21 and is again mixed with the saturated steam delivered by boiler drum 6 through conduit 7. The regulating member, illustrated in this instance as a valve means and'the firing of superheater 8 are so controlled that the ratio of the quantity of useful steam supplied by conduit 9 to the quantity of heating steam supplied through conduit 10 to the boiler drum 6 remains approximately constant in the case of all loads. The heating steam shunted around the boiler drum 6 .100

suffers practically no change in temperature in passing through the bypass pipe 20 in spite of the regulating member 21. It becomes mixed with the saturated steam supplied by the boiler drum in front of the jet apparatus 11 and the steam temperature, adjusted at this point and also before entry to the superheater 8, increases with decreasing load of the boiler. Simultaneously, however, the heat supplied to the superheater 8 decreases with decreasing load owing to the proper regulation of the superheater firing.

This super-heater may be provided with a gas firing, as indicated at 26, provided with suitable valve means 27, it being understood that no firing is provided for the boiler 6 which in the present instance operates according to the evaporator principle.

By the above arrangement I thus obtain, in spite of the fact that an equal volume of steam was supplied at all times by the jet apparatus, a quantity of useful steam which is regulated in accordance with load fluctuations and has a temperature independent of said load variations.

. A further advantage in causing a constant volume of vapor to traverse the superheater lies in obtaining an even distribution in said superheater which obviates to a considerable extent the danger of burning out tubes in this unit.

A second system of regulation may be effectedby bypassing a portion of the mixed steam of the jet apparatus 11 through a bypass pipe 22 having a regulating member 23 therein, back to conduit 7, which supplies saturated steam to said jet apparatus. This regulatingmeans is shown in Fig. 2 in combination with the regulating means shown in Fig. 1. In the second mentioned system of regulation the temperature at the super-- heater inlet remains practically constant even with part loads. The volume of steam flowing through the superheater is diminished with decreasing generation of steam. This system like the first mentioned system tends to keep the superheater outlet temperature constant.

In both systems variations in the coefficient of heat resulting from varying superheater inlet, furnace and gas temperatures due to part loads can be balanced by dividing the superheater surfaces into radiation and convection heating surfaces.

Since jet apparatus 11 effects a large pressure difference between the conduit leading to super-heater 8 and the conduit 7 leading to the jet apparatus, and a small pressure dif ference normally exists between conduits 10 and 8, when both systems are used in combination as shown in Fig. 2, rough control will be effected by valve 23 and finer regulation may be effected by valve 21. Regulating T valves 21 and 23 may be either manually or automatically controlled in accordance with the load. Shutting either valve 21 or 23 effects a change of the system from one the other.

The above described regulating means is applicable not only to a high pressure steam generator employing the ct apparatus as described, but also may be used in connection with centrifugal pumps with rigid characteristic lines, that is to say, with deficient regulating capacity.

Other regulating means may be used in combination with that disclosed in the pres ent invention such as those previously mentioned. namely, throttle members, on either side of the jet apparatus. In such a combination certain of the regulating elements may be used for rough control and others for the fine control.

While I have described my invention as relating especially to plants for generating steam. it will be understood that it is not limited thereto necessarily, but may be used in connection with plants which generate any other vapor.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

lVh at I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a vapor generating plant, the combination of a vapor generator, means for supplying a liquid to said generator, a superheater. a conduit connecting said generator to said super-heater. a jet apparatus provided in said conduit. means for generating and supplying superheated vapor to said jet anparatus whereby vapor is pumped from said generator to said superheater, a second conduit for supplying superheated vapor from said super-heater to a consumer. a third conduit between said second conduit and said vapor generator for supplying superheated steam to said vapor generator whereby liquid in said generator is evaporated and means for regulating the amount of vapor supplied to said vapor generator in terms of vapor demand comprising a by-pass between said third. and first named conduits which is connected to the latter ahead of said jet apparatus, and a valve means in said by-pass.

2. In a vapor generating plant, the combination of an evaporator, means for preheating and supplying a liquid to said evaporator. a super-heater, a conduit for connecting said generator to said superheater, a jet apparatus provided in said conduit, means for supplying superheated vapor to said jet apparatus whereby vapor is pumped from said generator to said superheater, a second conduit for supplying superheated vapor from said superheater to a consumer, a third conduit between said second conduit and said evaporator for supplying superheated steam to said evaporator whereby liquid in said evaporator is evaporated and means for regulating the superheated vapor supplied to said evaporator in terms of superheated vapor demand comprising a by-pass between said third and first named conduits and being connected to said first named conduit ahead of said jet apparatus, a valve means in said by-pass, a sesond by-pass arranged in said first named conduit with respect to said jet apparatus, and a valve means in said second by-pass.

In witness whereof, I have hereto set my hand this 4th day of June, 1929.

KURT ALLES 

